Fig. 1

Histopathologic findings in focal cortical dysplasia type IIb. Sections of frontal cortices resected from epileptic patients showed strongly dysplastic regions, which were characterized by both laminar and columnar architecture disorganization (a, b, c). Layer I was observed in most cases (b), but in others layer I was populated by abnormal cells (a, c). Both BCs (arrows in a, c, d, and g) and DNs (e) were observed, and together with the cortical dysplasia, indicated the diagnosis of FCD type IIb. Frequent findings included: HyNs (open arrowhead in a), apical dendrites not oriented towards the pia surface (PS) (b, f); blurring of the grey-white matter transition (a, g); heterotopic neurons in the white matter (h), and intense gliosis, shown here in the vicinity of a cluster of large, unstained neurons (arrowheads) (i). Cases: 8, a and e; 10, b, c, f, h; 1, d and g; 11, b, i. H&E staining: a, d, e, g; SMI 311 antibody, b, f, h; silver impregnation, c; anti-GFAP antibody, i. Scale bars: 40 μm: d, e; 100 μm: a, b, c, f, h, i; 200 μm: g